Electric switch



A. P. BALL ELECTRIC SWITCH Original Filed June l7-.. 1920 raven 0 Mmmmdv NJ April 22, 1924.

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Patented Apr. 22,1924.

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.ALBERT P. BALI, 0F DETROIT, MICHIGAN, SSIGNOB T0 SQUARE D COMPANY, OIF,y

DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

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Application filed J'une 17, 1920, Serial No. 389,552. Renewed February7, 1924.

ATo lall 'wwm t may concern.'

Be it known that I, ALBERT P. BALL', a citizen of the United States,residing at Detroit, in the county of Wayne and State of Michigan, haveinvented new and useful Im rovements in Electric Switches, of which thefollowing is a full, clear, concise, and exact description, referencebeing had to the accompanying drawing, forming a part of thisspecification.

My invention relates to electric switches and it has particular relationto apparatus of the character designated which embody means for ensuringa quick break between the contacts when connection therebetween isbroken as well as having in combination therewith, means for ensuring apositive complete closure of the switch contacts when the connection ismade.

The primary object of my invention is to provide means in combinationwith a switch of the character designated whereby the operatinginstrumentalities are so disposed that a decided resistance isinterposed to the accidental opening of the switch contacts by reason ofjars or otherwise. l

In the switch, hereinafter more specifically described. the positiveclosing connection is secured by the use of a slotted link cooperatingwith the switch operating handle and having a portion at its lower endwhich engages with a spring latch, thus holding the switch in the onposition until it is definitely opened by the operation of the operatinghandle. In this connection l provide springs so associated with themovable contacts of the switch that' the latter are continuously biasedtowards the open position thereof, and the switch will not thereforeremain closed until the movable contacts are thrown to such a lpositionthat the link hook and the spring latch are engaged whereby the tendencyof the movable contacts to snap to the open position thereof isovercome.

The hook and the spring latch are so disposed that the latter interposesa decided resistance to the closing of the movable contacts just beforethe latter make engagement with appropriate stationary contacts. It isnecessary, therefore, to exert additional pressure `on the operatinghandle in order to overcome this resistance. inasmuch as the movableswitch blades need only move a short distance thereafter to becompletely closed, this additional pressure, necessary'to overcome theresistance, results in the remainder of the blade travel beinginvoluntarily made with considerable rapidity. VThe operation justdescribed, therefore, results 1n a very advantageous quick actionv ofthe swltch contacts upon making the connection.

After the link has once engaged the spring latch a decided resistance isinterposed to the opening movement of the operating handle whereby theaccidental disconnection of the contacts by jarring or accidentalcontact 1s prevented. As I will hereinafter more fully point out thisfeature is obtained by the specific positioning of the operating-handlein a specically shaped slot formed in the aforementioned link.

For a better understanding of my invention reference may be had to theaccompanying drawing, in which: v

Fig. 1 is a plan view of a switch embodying my invention positioned inan enclosed casing, the/cover thereof being removed;

Figs. 2, 3 and Ltare elevational. sectional views taken on the line 2-2of Fig. 1, and illustrate the positions of the various switch operatingelements at-three different points in the operation thereof.

' A casing 1 is provided with a hinged cover n 2, the latter beingremoved in Fig. 1. Secured to the bottom of the casing 1 is aninsulating switch base 3 having fuse receiving clips 4 and 5 mountedthereupon, a fuse 6 extending between the said clips. and binding posts7 being associated with the clips adjacent one end wall of the casing 1.Stationary switch contacts 8 and 9 are likewise mounted upon said base,the contacts 8 being electrically connected to the fuse clips 4 andproviding a pivotal support for movable contact blades 10. Suitablebinding posts 11 are associated with the contacts 9. A cross-bar 12 isrigidly connected to the mov,- able blades 10 by clamps 13, the blades,clamps and cross arm moving together on the opening and closingmovements of the switch.

A switch operator comprises a handle 14 and a bail shaped portion 15formed integrally therewith, said operator. being adapted for rotationby reason of its pivotal su port in the sidei walls of the casing 1. Wasers 16 serve to pivotall position a link 17 on the cross-arm 12. T elatter has formed therein an arcuate slot 1S and is shaped at contactsits ylower end to provide a hook portion 19. Mounted on the base 3y is aspring 2() which is formed with a yoke portion 21 about which is loosely4journalled a roller 22. The crossarm of the bail shaped portion 15 isadapted to slide over one end to the other of the slot 18 as the link 17moves pivotally about the cross-arm 12.

Springs 23 are secured at one end to the switch posts 8 and have a yokeportion 24 which extends under the movable contacts 10 in such mannerthat the latter are constantly biased to an open position, shown inFior. 4.

laving described one embodiment of my invention the operation thereof isas follows: f

Upon a switch-closing movement of the handle 14 the switch operator 15slides in the slot 18 to the left hand end thereof, as shown in Fig. 2,and thereafter presses the movable contacts 10 downwardly until the hook19 of the link 17 comes' into contact with the roller 22 on the spring20. rlhis obstruction is met just yprior to the initial engagement ofthe switch contacts. Upon the application of additional pressure on theoperating handle the hook pushes the spring to the right and, as soon asthe roller is passed, the movable contacts make a definite and positiveengagement with the stationary comparatively rapidly. Thereafter, thenormal bias of the spring 20 effects a latching engagement between saidspring and the hook 19 whereby the opening action of the springs 23-isovercome. Thevposition of the various switch elements in the closed andlatched position of the movable contacts is shown in Fig. 2.

The contour of the hook is suchl that the resistance to the closing ofthe switch is interposed just before the blades enter the switch jaws.It is apparent therefore that unless the required additional pressure isapplied to the switch operating handle the blades will spring back underthe action of the spring 23 and the connection will not be made. Thisoperation is of distinct advantage in that it prevents incompleteclosing, and consequent high contact resistance between the contacts.Part 15 is forced into slot 18 by springing the link at 17.

On the other hand, when it'is desired to open the switch, the operatinghandle is moved td the right until the part 15 engages the right handend of the slot 18 whereupon the link 17 'is rotated about its pivotalsupport on the arm 12 to disengage the hook from its latching relationwith the spring 20. The position of the switch elements just after thelink has been rotated to effect' said disengagement is shown in Fig. 3.

Immediately upon said disengagement the springs 23 function to snap theswitch blades open, the length of the slot 18 being such that t?, lLacasse also provides tension in two directions which is beneficial inproviding the desirable features herein described with respect to theshape of the slot in the link. i

In order to prevent a switch lopening movement of the operating handledue to its own weightV or because of vibration whereby the member 15might reach the end of the slot and through jarring or accidentalcontact unlatch the link, the slot is so shaped that the operating leverin traversing it from one-end to the other acts so as to' latch the hookon the link more securely with the spring 20. The increased resistancethus provlded prevents the operating handle from jarringdownwardly whenmy switch is mounted is an upright position, inasmuch as the handle inits initial movement through the slot instead of tending to unlatch theswitch, emphasizes the engagement between the hook and the spring. It isnecessary, therefore, to makea definite positive movement of the handle14 whereby the member 15 is moved from one end of the slot 18 to theother before the latching engagement is unlocked and the movable bladespermitted to snap open. j

While l have described but vone embodi ment of my invention it isapparent that many modifications therein may occur to -those skilled inthe artand I desire, therefore, that it be limited only by the showingof the prior art and by the scope of the appended claims. j

Having thus described my, invention what l claim as new and desire tosecure by 'Letters Patent is:

1. In a switch, stationary and movable contacts, an operator, meansconnecting said movable contacts and said operator, means forinterposing resistance to the closing of said movable conta-cts, saidconnecting means so associating said movable contacts and said operatorthat a definite positive movement must be applied to said operator toopen said contacts and being further so associated that an initialswitch opening movement of said operator emphasizes said resistance,whereby accidental partial movement of the operator does not open saidswitch.

2. ln a switch, stationary and movable contacts, an operator, meansconnecting said movable contacts and said operator, means forinterposing resistance to the closing of said movable contacts andthereafter comprising a retaining member for said contacts, saidconnecting means so associating said movable contacts and said operatorthat, after said contacts have been definitely retained in closed link,connecting said movable contacts and said operator, means forinterposing resistance to the closin of said movable contacts and forthereal er latching the same through said link, said connecting means soassociating said movable contacts and said operator that a definitepositive movement must be applied to said operator to open said contactswhereby accidental movement of the latter does not open said switch.

4. In a switch, stationary and movable contacts, an operator, meansconnecting said movable contacts and said operator, comprising a linkhaving a slot therein in which part of said operator slides, and meansfor interposing resistance to the closing movement of said movablecontacts and for thereafter engaging one end of said link to lock saidcontacts in closed position,

said slot being so shaped that said operator in making a switch-openingmovement initially emphasizes said locking.

5. In a switch, stationary and movable contacts, an operator, meansconnecting ywhereby, accidental movement of the latter does not opensaid switch.

6. In a switch, .stationary and movable contacts, an operator, meansconnecting said movable-contacts and said operator, means for,lockingsaid movable contacts in closed position, rand means whereby aninitial switch-opening movement of the -operator emphasizes thev lockingand thus interposes resistance to an accidental movement of saidoperator i-n a switch-opening direction.

7. In av switch, stationary and movable contacts, an operator, means forlookin said movable contacts in closed position, an

means for connecting said movable contacts and said operator comprisinga link having a slot therein in which said operator slides, said slotbeing arcuate in such direction that resistance is interposed to anaccidental opening of said switch whereby a positive engagement of saidoperatorwith the end of said slot is necessary to unlock said co-ntacts'and open said sw1tch.

8. In a switch, stationary contacts, mov- -able contacts biased to anopen position,

an operator, a pivoted link having a slot therein for connecting saidoperator to said contacts, and a latching device for said movablecontacts comprising a spring having an oscillatory yoke portion, one endof said link being adapted to engage said yoke portion Iand to be lockedby the normal bias thereof.`

9. In a switch, stationary contacts, movable contacts fbiased to an`open position, an operator, a pivoted link having a slot therein forconnecting said operator to said contacts, and a latching device forsaid movable contacts comprising a spring having an oscillatoryyokeportion provided with a roller, one end of said link being adapted toengage said roller and to be locked by the normal bias of said spring.

l0. In a switch, stationary contacts, movable contacts biased to an openposition, an operator, a pivoted linkhaving a 'slot therein forconnecting said operator to said contacts, and a latching device forsaid movable contacts comprising a spring having an oscillatory yokeportion, one end of said link being adapted to engage said yoke portionand to be locked by the normal bias thereof, and said slot being arcuatef by an accidental or incomplete switch-opening movement of saidoperator meets an 1n'- creased resistance. In witness whereof, I havehereunto subscribed my name.

. ALBERT P. BALL. Witnesses:

JOHN B. PLATE, G. H.I JAcoBsoN.

